Re: Coil photograpy idea

to: Mike

Many years ago we once used a 6,000 frames/sec camera to shoot the discharge
of a large TC.  The frames clearly illustrate the "growth" pattern as the
spark grows out of the hv terminal.  Never did it with video though.



-----Original Message-----
From: Tesla List <tesla-at-pupman-dot-com>
To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
Date: Friday, March 05, 1999 6:09 PM
Subject: Coil photograpy idea

>Original Poster: wwl-at-netcomuk.co.uk (Mike Harrison)
>I just had an idea about a new way to get potentially good , or at
>least diffrent. pictures of a coil firing.
>I have a CCTV camera which has a fast shutter mode, and also a genlock
>(external sync) input. If I generate a dummy frame sync for it to lock
>onto, derived from the mains frequency via an adjustable phase delay,
>it ought to be possible to take fairly fast (down to about 1mSec I
>think) 'snapshots' at fairly precise, repeatable intervals relative to
>the mains cycle, and therefore observe different stages in the spark
>formation, as well as observing the effects of such things as spark
>gap firing jitter etc. The result could either be recorded on video
>tape for frame-by frame analysis, or better, (unless a VCR with very
>good stillframe is used), digitised to hard disk.
>(I also have a very good zoom lens so I can keep it well away from the
>coil :-)
>Has anyone tried anything like this before ?
>I've just bought a PCI video capture card, but probably won't have
>time to play with it for a couple of weeks

>but I definately will try this & will post any news.